1. Field of the Invention
The present disclosure relates to a display device comprising a panel divided into different panel portions and a driving method thereof. More specifically, the present disclosure relates to a display device comprising two or more panel portions equipped with touch functions and a driving method thereof.
2. Description of the Prior Art
As information oriented society has been developed, demands for displays for displaying an image are increasing. Thus, various flat displays such as a liquid crystal display (LCD), plasma display panel (PDP), and organic light emitting display (OLED) have been used recently.
The liquid crystal display (LCD) displays an image by controlling light transmittance of a liquid crystal using an electric field. The liquid crystal display (LCD) includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix form and a driving circuit for driving thereof.
A plurality of gate lines (GLs) and data lines (DLs) are intersected therebetween and a thin film transistor (TFT) is formed for driving the liquid crystal cell (Clc) at every intersection between the gate lines (GLs) and the data lines (DLs) on a pixel array of the liquid crystal panel. A storage capacitor is formed for keeping a voltage of the liquid crystal cell (Clc) on the liquid crystal panel. The liquid crystal cell (Clc) comprises a pixel electrode, a common electrode and a liquid crystal layer. The electric field is applied to the liquid crystal layer of the liquid crystal cells (Clc) by both a data voltage applied to the pixel electrode and a common voltage (Vcom) applied to the pixel. The liquid crystal panel displays the image by controlling the quantity of light to penetrate the liquid crystal cell by the electric field.
The driving circuit comprises a gate driving circuit in order to provide a gate output signal for the gate lines and a data driving circuit in order to sequentially provide a video signal or a data voltage for the data lines. The data driving circuit drives the data lines to provide the data voltage for the liquid cells (Clc). The gate driving circuit sequentially drives the gate lines to select the liquid crystal cells of one horizontal line among all of them for which the data voltage will is provided.
The gate driving circuit comprises a gate shift register consisted of a plurality of stages in order to sequentially generate the gate signals. Each stage of the gate shift register outputs a gate clock signal (Vout) generated based on a low voltage (Vss) level and a gate clock signal (CLK) by alternately performing a charging and discharging. Each of output ends and each of the gate lines are connected with each other line by line. The gate signal of a first level from the stages is sequentially generated once per frame and supplied to the corresponding gate line.
On the other hand, for slimming a mobile terminal such as a smart phone, a tablet PC and the like, there have been developed and used a touch screen-integrated display device inside which an element consisted of the touch screen is built-in to provide a touch input function in the display device.
Such touch screen-integrated display device may be expressed as an in-cell type touch panel. In such touch screen-integrated display device, an electrode for sensing touch is commonly used for the common electrode and the common electrode supplies a common voltage to a pixel during a pixel output time and operates as a touch electrode during a touch sensing time.
Such touch-panel-integrated display device typically performs one touch sensing during one frame (period) which is equal to a screen refresh rate of the display panel or one period of a frame frequency.
In other words, if the frame frequency/rate is 60 Hz, Such touch-panel-integrated display device performs both an on/off driving of the pixel through driving the N of gate signals consisted of the panel and touch driving at the end within 1/60 s time interval. Thus, the touch sensing frequency (Touch Report Rate) will become the 60 Hz.
However, if the user's touch operation becomes fast and a response speed of the touch operation is considered, the touch sensing frequency of 60 Hz (namely, touch-sensing of 60 times in one second) may be insufficient. Therefore, the touch sensing frequency needs to be improved.